Tillage practices since the first settlers arrived, have reduced the fungi in the soil, even though they began with organic farming methods. Bare soils expose fungi to high temperatures which reduces them further. Then the use of artificial fertilisers, fungicides, pesticides and herbicides have pretty much destroyed them. In families that have been on the same land for generations, the older folk can remember when they were able to pick copious mushrooms from their farms. Not any more!
Nearly 90 percent of all land plants are believed to interact in some way with fungi. There are an estimated 3 million fungi on the planet but only around 120,000 have been classified. This means there is still a large gap in our knowledge. Classification methods have changed. Mycologists used to classify fungi based only on their morphology but now DNA methods are being used.
Science is only just beginning to understand the complex relationships between plants and fungi. We know there are fungi that are in AMF Arbuscular Mycorrhizal Fungi - highly branched structures for nutrient exchange inside the plant. AMF produce the glycoprotein glomalin, a major store of soil carbon EM Endomycorrhiza - variable and have been further classified as arbuscular, ericoid, arbutoid, monotropoid, and orchid mycorrhizas DSE Dark Septate Endophytes - melanized, septate, hyphae that colonize roots intracellularly or intercellularly EcM Ectomycorrhizal - do not penetrate their host's cell walls but surround their roots groupings.
One of the most well-known groups of beneficial soil fungi are AMF. AMF are thought to work synergistically with plants by increasing the availability of water and nutrients, and sharing of chemicals to protect against pathogens and pests. In exchange, plants roots provide carbohydrates that they have made from CO2 and sunlight and shelter for the fungi.